Mechanical Catalysis: Methods of Enzymatic, Homogeneous, and Heterogeneous Catalysis

CONTRIBUTORS.

GLOSSARY.

1. Introduction to Thermodynamic (Energy-Dependent) and Mechanical (Time-Dependent) Processes: What Are They and How Are They Manifested in Chemistry and Catalysis? (Gerhard F. Swiegers).

1.1 Thermodynamic (Energy-Dependent) and Mechanical (Time-Dependent) Processes.

1.2 What Is a Thermodynamic Process?

1.3 What Is a Mechanical Process?

1.4 The Difference between Energy-Dependent (Thermodynamic) and Time-Dependent (Mechanical) Processes.

1.5 Time- and Energy-Dependence in Chemistry and Catalysis.

1.6 The Aims, Structure, and Major Findings of this Series.

2. Heterogeneous, Homogeneous, and Enzymatic Catalysis. A Shared Terminology and Conceptual Platform. The Alternative of Time-Dependence in Catalysis (Gerhard F. Swiegers).

2.1 Introduction: The Problem of Conceptually Unifying Heterogeneous, Homogeneous, and Enzymatic Catalysis? Trends in Catalysis Science.

2.2 Background: What Is Heterogeneous, Homogeneous, and Enzymatic Catalysis.

2.3 Distinctions Within Homogeneous Catalysis: Single-Centered and Multicentered Homogeneous Catalysis.

2.4 The Distinction between Single-Site/Multisite Catalysts and Single-Centered/MultiCentered Catalysts in Heterogeneous Catalysis: An Important Convention Used in This Series.

2.5 The Alternative of Time-Dependence in Catalysis.

3. A Conceptual Description of Energy-Dependent (“Thermodynamic”) and Time-Dependent (“Mechanical”) Processes in Chemistry and Catalysis (Gerhard F. Swiegers).

3.1 Introduction.

3.2 Theoretical Considerations: Common Processes in Uncatalyzed Reactions.

3.3 Theoretical Considerations: Common Processes in Catalyzed Reactions.

4. Time-Dependence in Heterogeneous Catalysis. Sabatier’s Principle Describes Two Independent Catalytic Realms: Time-Dependent (“Mechanical”) Catalysis and Energy-Dependent (“Thermodynamic”) Catalysis (Gerhard F. Swiegers).

4.1 Introduction.

4.2 Sabatier’s Principle in Heterogeneous Catalysis.

4.3 Exceptions to Sabatier’s Principle.

4.4 Sabatier’s Principle in Homogeneous Catalysis.

4.5 Conclusions. Sabatier’s Principle Describes Two Independent Catalytic Domains: Energy- and Time-Dependent Catalysis.

5. Time-Dependence in Homogeneous Catalysis. 1. Many Enzymes Display the Hallmarks of Time-Dependent (“Mechanical”) Catalysis. Nonbiological Homogeneous Catalysts Are Typically Energy-Dependent (“Thermodynamic”) Catalysts (Robin Brimblecombe, Jun Chen, Junhua Huang, Ulrich T. Mueller-Westerhoff and Gerhard F. Swiegers).

5.1 Introduction.

5.2 Historical Background: Are Enzymes Generally Energy-Dependent or Time-Dependent Catalysts?

5.3 The Methodology of This Chapter: Identify, Contrast, and Rationalize the Common Processes Present in Biological and Nonbiological Homogeneous Catalysts.

5.4 Does Michaelis–Menten Kinetics in Enzymes Indicate that They Are Time-Dependent Catalysts?

5.5 Other General Characteristics of Catalysis by Enzymes and Comparable Nonbiological Homogeneous Catalysts.

5.6 Rationalization of the Underlying Processes. The Mechanism of Action in Time-Dependent and Energy-Dependent Catalysts.

5.7 All Generalizations Support Time-Dependence in Enzymes.

5.8 Time-Dependence in a Nonbiological Catalyst Generates the Distinctive Properties of Enzymes.

5.9 Conclusion: Many Enzymes Are Time-Dependent Catalysts.

6. Time-Dependence in Homogeneous Catalysis. 2. The General Actions of Time-Dependent (“Mechanical”) and Energy-Dependent (“Thermodynamic”) Catalysts (Robin Brimblecombe, Jun Chen, Junhua Huang, Ulrich T. Mueller-Westerhoff, and Gerhard F. Swiegers).

6.1 Introduction.

6.2 Time- and Energy-Dependent, Multicentered Homogeneous Catalysts.

6.3 The Action of Energy-Dependent, Multicentered Homogeneous Catalysts.

6.4 The Action of Time-Dependent, Multicentered Homogeneous Catalysts.

6.5 The Importance of Recognizing Time-Dependent Catalysis.

6.6 Time-Dependent Catalysis Is Very Different to Energy-Dependent Catalysis and Therefore Seems Unfamiliar.

6.7 Conclusions for Biology.

6.8 Conclusions for Homogeneous Catalysis.

6.9 The “Ideal” Homogeneous Catalyst.

6.10 Conclusions for the Conceptual Unity of the Field of Catalysis.

7. Unifying the Many Theories of Enzymatic Catalysis. Theories of Enzymatic Catalysis Fall into Two Camps: Energy-Dependent (“Thermodynamic”) and Time-Dependent (“Mechanical”) Catalysis (Gerhard F. Swiegers).

7.1 Introduction.

7.2 Theories of Enzymatic Catalysis.

7.3 Theories Explaining Enzymatic Catalysis Fall into Two Camps: Energy-Dependent and Time-Dependent Catalysis.

7.4 Studies Verifying Pauling’s Theory in Model Systems Are Correct, but Describe Energy-Dependent and not Time-Dependent Catalysis.

7.5 The Anomaly Described in the Spatiotemporal Hypothesis Originates, in Part, from the Onset of Time-Dependence.

8. Synergy in Heterogeneous, Homogeneous, and Enzymatic Catalysis. The “Ideal” Catalyst (Gerhard F. Swiegers).

8.1 Introduction.

8.2 Synergy in Heterogeneous Catalysts.

8.3 Single-Centered Nonbiological Homogeneous Catalysts and Their ‘Mutually Enhancing’ Synergies.

8.4 Multicentered, Energy-Dependent Homogeneous Catalysts and Their Functionally Complementary Synergies.

8.5 Enzymes and Their Functionally Convergent Synergies.

8.6 Biomimetic Chemistry and Its Pseudo-Convergent Synergies.

8.7 The Spectrum of Synergistic Action in Homogeneous Catalysis.

8.8 Synergy in Catalysis Is Conceptually Related to Other Synergistic Processes in Human Experience.

9. A Conceptual Unification of Heterogeneous, Homogeneous, and Enzymatic Catalysis (Gerhard F. Swiegers).

9.1 Introduction.

9.2 Diffusion-Controlled and Reaction-Controlled Catalysis.

9.3 The Diversity of Catalytic Action in Heterogeneous Catalysts.

9.4 The Diversity of Catalytic Action in Nonbiological Homogeneous Catalysts.

9.5 The Diversity of Catalytic Action in Enzymes.

9.6 Heterogeneous Catalysis and Enzymatic Catalysis Has, Effectively, Involved Combinatorial Experiments that Have Produced Time-Dependent Catalysts. Nonbiological Homogeneous Catalysis Has Not.

9.7 Homogeneous and Enzymatic Catalysts Are the 3-D Equivalent of 2-D Heterogeneous Catalysts.

9.8 A Conceptual Unification of Heterogeneous, Homogeneous, and Enzymatic Catalysis.

10. The Rational Design of Time-Dependent (“Mechanical”) Homogeneous Catalysts. A Literature Survey of Multicentered Homogeneous Catalysis (Junhua Huang and Gerhard F. Swiegers).

10.1 Introduction.

10.2 The Rational Design of Time-Dependent Homogeneous Catalysts.

10.3 Elements of Rational Design in Multicentered Catalysis.

10.4 A Review of Nonbiological, Multicentered Molecular Catalysts Described in the Chemical Literature.

11. Time-Dependent (“Mechanical”), Nonbiological Catalysis. 1. A Fully Functional Mimic of the Water-Oxidizing Center (WOC) in Photosystem II (PSII) (Robin Brimblecombe, G. Charles Dismukes, Greg A. Felton, Leone Spiccia, and Gerhard F. Swiegers).

11.1 Introduction.

11.2 The Physical and Chemical Properties of the Cubanes 1a-b.

11.3 Nafion Provides a Means of Solubilizing and Immobilizing Hydrophobic Metal Complexes.

11.4 Photoelectrochemical Cells and Dye-Sensitized Solar Cells for Water-Splitting.

11.5 Photocatalytic Water Oxidation by Cubane 1b Doped into a Nafion Support.

11.6 The Challenge of Dye-Sensitized Water-Splitting.

11.7 The Mechanism of the Catalysis.

11.8 Conclusions.

12. Time-Dependent (“Mechanical”), Nonbiological Catalysis. 2. Highly Efficient, “Biomimetic” Hydrogen-Generating Electrocatalysts (Jun Chen, Junhua Huang, Gerhard F. Swiegers, Chee O. Too, and Gordon G. Wallace).

12.1 Introduction.

12.2 Monomer and Polymer Preparation.

12.3 Catalytic Experiments.

12.4 Conclusions: A Combinatorial “Statistical Proximity” Catalyst Was Obtained as a Bulk, Hybrid Homogeneous–Heterogeneous Catalyst.

13. Time-Dependent (“Mechanical”), Nonbiological Catalysis. 3. A Readily Prepared, Convergent, Oxygen-Reduction Electrocatalyst (Jun Chen, Gerhard F. Swiegers, Gordon G. Wallace, and Weimin Zhang).

13.1 Introduction.

13.2 Cofacial Diporphyrin Oxygen-Reduction Catalysts.

13.3 Vapor-Phase Polymerization of Pyrrole as a Means of Immobilizing High Concentrations of Monomeric Catalytic Groups at an Electrode Surface.

13.4 Preparation and Catalytic Properties of PPy-3.

13.5 PPy-3 as a Fuel Cell Catalyst.

13.6 Conclusions.

Appendix A Why Is Saturation Not Observed in Catalysts that Display Conventional Kinetics?

Appendix B Graphical Illustration of the Processes Involved in the Saturation of Molecular Catalysts.

Index.